Charge recovery bi-phasic control for tissue stimulation

• US 10,537,740 B2
• Filed: 08/11/2016
• Issued: 01/21/2020
• Est. Priority Date: 11/02/2009
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Carbunaru, Rafael, Bradley, Kerry
• Primary Examiner(s): Koharski, Christopher
• Assistant Examiner(s): Bays, Pamela M.
• Application Number:
  US15/234,866
• Publication Number:
  US 20160346550A1
• Time in Patent Office: 1,258 Days
• Field of Search: 607 72
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/36128 Control systems
• CPC Class Codes: A61N 1/36178 Burst or pulse train parameters
• CPC Class Codes: A61N 1/36185 Selection of the electrode configuration

Abstract

A method and external control device for providing therapy to a patient using first and second electrodes implanted within the patient is provided. A train of electrical multi-phasic pulses is generated. A first electrical current is sourced from the second electrode and at least a portion of the first electrical current is sunk to the first electrode during a stimulation phase of each multi-phasic pulse, thereby therapeutically stimulating a first tissue region adjacent the first electrode. A second electrical current is sourced from the first electrode and at least a portion of the second electrical current is sunk to the second electrode during a charge recovery phase of each multi-phasic pulse, thereby recovering at least a portion of the charge that had been injected into the patient during the stimulation phase of each multi-phasic pulse, and therapeutically stimulating a second tissue region adjacent the second electrode.

Claims

1. A method of providing therapy to a patient using electrodes implanted in a patient, the electrodes including a first electrode, a second electrode and a third electrode implanted within the patient, the method comprising:

generating an electrical waveform with a first phase and a second phase, wherein a first electrical current is provided by the first phase and a second electrical current is provided by the second phase;

stimulating a first tissue region during the first phase of the electrical waveform by sourcing a portion of the first electrical current as anodic current from at least the second electrode and another portion of the first electrical current as anodic current from the third electrode and sinking at least a portion of the first electrical current as cathodic current to the first electrode; and

stimulating a second tissue region during the second phase of the electrical waveform by sourcing a portion of the second electrical current as anodic current from the first electrode and another portion of the second electrical current anodic current from the third electrode and sinking at least a portion of the second electrical current as cathodic current to the second electrode during the second phase, wherein the sourcing the portion of the second electrical current as anodic current from the first electrode recovers at least a portion of injected charge during the first phase of the electrical waveform.

2. The method of claim 1, wherein

a first tissue region adjacent to the first electrode has a first cathodic stimulation threshold for cathodic electrical current and a first anodic stimulation threshold for anodic electrical current, a second tissue region adjacent to the second electrode has a second cathodic stimulation threshold for cathodic electrical stimulation and a second anodic stimulation threshold for anodic electrical current, and a third tissue region adjacent to the third electrode has a third cathodic stimulation threshold for cathodic electrical stimulation and a third anodic stimulation threshold for anodic stimulation;

the at least the portion of the first electrical current sunk as cathodic current to the first electrode is greater than the first cathodic stimulation threshold;

the at least the portion of the second electrical current sunk as cathodic current to the second electrode is greater than the second cathodic stimulation threshold;

the portion of the first electrical current sourced from the second electrode during the first phase is less than the second anodic stimulation threshold, and the portion of the second electrical current sourced from the first electrode during the second phase is less than the first anodic stimulation threshold.

3. The method of claim 2, wherein the second cathodic stimulation threshold is different from the first cathodic stimulation threshold.

4. The method of claim 3, wherein electrical current between the first and second electrodes during the first and second phase does not cause discomfort due to excessive stimulation of the first tissue region and the second tissue region.

5. The method of claim 4, further comprising performing at least one of the following steps:

sinking another portion of the first electrical current to a fourth electrode implanted within the patient during the first phase if the first cathodic stimulation threshold for the first tissue region is less than the second cathodic stimulation threshold for the second tissue region;

or

sinking another portion of the second electrical current to the fourth electrode implanted within the patient during the second phase if the second cathodic stimulation threshold for the second tissue region is less than the first cathodic stimulation threshold for the first tissue region.

6. The method of claim 5, further comprising performing at least one of the following steps:

adjusting the duration of the first phase to be longer than the duration of the second phase if the first stimulation threshold for the first tissue region is less than the second stimulation threshold for the second tissue region; and

adjusting the duration of the second phase to be longer than the duration of the first phase if the second stimulation threshold for the second tissue region is less than the first stimulation threshold for the first tissue region.

7. The method of claim 2, wherein the other portion of the first electrical current sourced from the third electrode during the first phase is less than the third anodic stimulation threshold, and the other portion of the second electrical current sourced from the third electrode during the second phase is less than the third anodic stimulation threshold.

8. The method of claim 1, wherein the first and second tissue regions are contiguous.

9. The method of claim 1, wherein no electrical current is conveyed between the first electrode and the second electrode during a third phase between the first phase and the second phase.

10. The method of claim 9, wherein the third phase is at least one-half of the first phase.

11. The method of claim 9, wherein the combination of the first phase, second phase, and third phase form at least one bi-phasic pulse.

12. The method of claim 11, wherein the at least one bi-phasic pulse is symmetrical.

13. The method of claim 12, wherein the at least one bi-phasic pulse is asymmetrical.

14. The method of claim 1, wherein the stimulating the second tissue region includes:

sinking another portion of the first electrical current to a third electrode implanted within the patient during the first phase of the electrical waveform, wherein a third tissue region adjacent the third electrode is not stimulated; and

sourcing a third electrical current from the third electrode and sinking at least a portion of the third electrical current to the second electrode during the second phase of the electrical waveform, thereby, in combination with the at least a portion of the second electrical current sunk to the second electrode, recovering the at least a portion of the injected charge during the first phase of the electrical waveform.

15. The method of claim 1, wherein each of the first and second tissue regions comprises spinal cord tissue.

16. A method of providing therapy to a patient using first and second electrodes implanted within the patient, the method comprising:

generating an electrical waveform with a first phase and a second phase;

sourcing a first electrical current from the second electrode and sinking at least a portion of the first electrical current to the first electrode during the first phase to therapeutically stimulate a first tissue region adjacent the first electrode, the first tissue region having a first cathodic stimulation threshold;

sourcing a second electrical current from the first electrode and sinking at least a portion of the second electrical current to the second electrode during the second phase to recover at least a portion of the charge that had been injected into the patient during the first phase to stimulate a second tissue region adjacent the second electrode, the second tissue region having a second cathodic stimulation threshold different from the first cathodic stimulation threshold, wherein electrical current between the first and second electrodes during the first and second phase does not cause discomfort due to excessive stimulation of the first tissue region and the second tissue region; and

performing at least one of the following steps;

sinking another portion of the first electrical current to a third electrode implanted within the patient during the first phase if the first cathodic stimulation threshold for the first tissue region is less than the second cathodic stimulation threshold for the second tissue region; and

sinking another portion of the second electrical current to a third electrode implanted within the patient during the second phase if the second cathodic stimulation threshold for the second tissue region is less than the first cathodic stimulation threshold for the first tissue region.

17. The method of claim 16, further comprising performing at least one of the following steps:

adjusting the duration of the first phase to be longer than the duration of the second phase if the first cathodic stimulation threshold for the first tissue region is less than the second cathodic stimulation threshold for the second tissue region; and

adjusting the duration of the second phase to be longer than the duration of the first phase if the second cathodic stimulation threshold for the second tissue region is less than the first cathodic stimulation threshold for the first tissue region.

18. The method of claim 16, wherein each of the first and second tissue regions comprises spinal cord tissue.

19. The method of claim 16, wherein no electrical current is conveyed between the first electrode and the second electrode during a third phase between the first phase and the second phase.